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Tag: Nearly-Zero Energy Buildings (page 1 of 2)

All New Homes Will Be Nearly Zero Energy Buildings (NZEB)

Amendments to Part L of the Building Regulations (relating to the conservation of fuel and energy in dwellings) will come into effect on 01 November 2019.

All new homes will have a typical Building Energy Rating (BER) of A2 and will be 70% more energy efficient and emit 70% less carbon dioxide than 2005 performance levels.

What is a Nearly-Zero Energy Building (NZEB)?

‘Nearly zero-energy building’ means a building that has a very high energy performance. The nearly zero or very low amount of energy required should be covered to a very significant extent by energy from renewable sources, including energy from renewable sources produced on-site or nearby.

Are there any exceptions to the new regulations?

Yes, but only if planning approval or permission has been applied for on or before 31st October 2019 and substantial work has been completed by 31st October 2020.

“Substantial work has been completed” means that the structure of the external walls of the dwelling has been erected.

 What are the key changes to TGD L Dwellings 2019?

  • MPEPC (Maximum Permitted Energy Performance Coefficient)=0.30, in order to achieve the acceptable primary energy consumption rate.
  • MPCPC (Maximum Permitted Carbon Performance Coefficient)=0.35, to demonstrate that an acceptable CO2 emission rate has been achieved.
  • Where a dwelling undergoes major renovation, the energy performance of the whole dwelling should be improved to Cost Optimal level insofar as this is technically, functionally and economically feasible.
  • Introduction of a Renewable Energy Ratio (RER) of 20%.
  • Reduction of air permeability backstop from 7m3 /hr/m2 to 5m3 /hr/m2.
  • Table 1- Reduction of wall and floor backstop U-Value from 0.21W/m2K to 0.18 W/m2K.
  • Table 1- Reduction of window backstop U-Value from 1.6 W/m2K to 1.4 W/m2K.
  • Inclusion of guidance to avoid overheating in dwellings.
  • Par 1.3.2.4 – removal of variation of U-Value with percentage glazing.
  • Introduction of calculation of Ru value for corridors in apartments.

How can compliance be achieved?

The correct specifications need to be prepared by your Architect to your specific project. Compliance is then demonstrated using the DEAP (Dwelling Energy Assessment Procedure) software.

Below is an example prepared by the Department of Housing, Planning and Local Government for a semi-detached dwelling with 126 sq.m. and with heat pump for space heating and continuous mechanical extract ventilation.

NZEB example specification
Semi-detached dwelling with 126 sq.m. and with heat pump for space heating and continuous mechanical extract ventilation

A nearly zero energy buildings (NZEB) future – Minister English reminds construction sector to be prepared for new building regulations on energy efficiency

What’s All the Fuss About the Revised Energy Performance of Buildings Directive

Overview of Key Changes to TGD L – Dwellings 2019

What’s All the Fuss About the Revised Energy Performance of Buildings Directive

The amendment of the Energy Performance of Buildings Directive (EPBD) is one of the most important changes that has occurred in the EU buildings sector in the last 16 years.

Under the revised Energy Performance of Buildings Directive (EPBD):

  • EU countries will have to establish stronger long-term renovation strategies, aiming at decarbonising the national building stocks by 2050, and with a solid financial component.
  • A common European scheme for rating the smart readiness of buildings, optional for Member States, will be introduced.
  • Smart technologies will be further promoted, for instance through requirements on the installation of building automation and control systems and on devices that regulate temperature at room level.
  • E-mobility will be supported by introducing minimum requirements for car parks over a certain size and other minimum infrastructure for smaller buildings.
  • EU countries will have to express their national energy performance requirements in ways that allow cross-national comparisons.
  • Health and well-being of building users will be promoted, for instance through an increased consideration of air quality and ventilation.

Other requirements under the Energy Performance of Buildings Directive include:

  • All new buildings must be nearly zero-energy buildings by 31 December 2020.
  • Energy performance certificates must be issued when a building is sold or rented, and they must also be included in all advertisements for the sale or rental of buildings.
  • EU countries must establish inspection schemes for heating and air conditioning systems or put in place measures with equivalent effect.
  • EU countries must set cost-optimal minimum energy performance requirements for new buildings, for the major renovation of existing buildings, and for the replacement or retrofit of building elements (heating and cooling systems, roofs, walls and so on).
  • EU countries must draw up lists of national financial measures to improve the energy efficiency of buildings.

What is the challenge?

  • The Commission reached an agreement that includes a binding energy efficiency target for the EU for 2030 of 32.5%.
  • The risk of the directive being ineffective is high if countries and local authorities do not enforce it correctly.
  • Around 200 million buildings need to be renovated. EU countries must make energy efficient renovations to at least 3% of the total floor area of buildings owned and occupied by central government.
  • EU governments should only purchase buildings which are highly energy efficient.
  • EU countries must draw up long-term national building renovation strategies which can be included in their National Energy Efficiency Action Plans.
  • Member states are to provide for set system requirements in respect to installation, sizing, adjustment and controls. This applies to heating systems, hot water, air conditioning and large ventilation systems.
  • Cost optimal performance – the integration between cost optimality and high performance technical solutions underpins the deployment of NZEBs.

Overview of Key Changes to TGD L – Dwellings 2019


Technical Guidance Documents are published to accompany each part of the Building Regulations in Ireland indicating how the requirements of that part can be achieved in practice.

Technical Guidance Document L (TGD L) indicates the requirements for Conservation of Fuel and Energy.

A new TGD L is due to be published in 2019. The new document follows a revision of the Energy Performance of Buildings Directive (EPBD). Member States have until March 2020 to translate into national law all the new requirements from the EU energy efficiency legislation affecting buildings.

Draft Transitional Arrangements:

  • NZEB and TGD L 2019 Dwellings to apply to new Dwellings commencing construction from 1st November 2019 subject to transition.
  • Transitional arrangements to allow TGD L 2011 – Dwellings to be used where planning approval or permission has been applied for on or before 31st October 2019 and substantial completion is completed within 1 year i.e. by 31st October 2020.

Overview of key changes to TGD L Dwellings 2019:

  • Introduction of NZEB (Nearly-Zero Energy Building), MPEPC (Maximum Permitted Energy Performance Coefficient)=0.30, MPCPC (Maximum Permitted Carbon Performance Coefficient)=0.35
  • Introduction of Major Renovations to a cost optimal level where technically, economically and functionally feasible
  • Introduction of a Renewable Energy Ratio (RER) of 20% as per ISO EN 52000 (to replace 10kWh/m2 /yr).
  • Reduction of air permeability backstop from 7m3 /hr/m2 to 5m3 /hr/m2
  • Table 1- Reduction of wall and floor backstop U-Value from 0.21W/m2K to 0.18 W/m2K
  • Table 1- Reduction of window backstop U-Value from 1.6 W/m2K to 1.4 W/m2K
  • Inclusion of guidance to avoid overheating in dwellings
  • Par 1.3.2.5 – removal of variation of U-Value with percentage glazing • Introduction of calculation of Ru value for corridors in apartments.

The draft TGD L – Dwellings 2019 can be accessed here.

The current TGD L – Dwellings 2011-2017 can be accessed here.

Minimum BER rating for new houses built in 2019.

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